Electric circuit breaker



Ap 9, 1946. s. R. sMrrH, JR

ELECTRIC CIRCUIT BREAKER Original Filed Sept. 26

Inventor: SdneyRSmbh JT?, )o 5/ J y Hi; Attorney 'and hence require replacement thereof.

lReued dApr. 9, 1946 ELECTRIC CIRCUIT BREAKER Sidney R. Smith, Jr., Pittsfield, Mass., assignor to General Electric Company, a corporation of New York Original No. 2,357,853, dated September 12, 1944.

Serial No. 459,791, September 26, 1942. Application for reissue December 1, 1944, Serial No.

(ci. 20o-116) 24 Claims.

My invention relates to electric circuit breakers and more particularly to such circuit vbreakers which are adapted for use in place of the conventional fuse cutout devices. Specifically, my invention is an improvement on my prior copending application Serial No. 334,629, filed May ll, 1940, and assigned to the same assignee as the present application.

Fuse cutout devices have been used to a large extent in the protection of high tension electric circuits. Devices of this kind in general comprise replaceable fusible means mounted within a suitable holder and they are usually located in close proximity to the high tension conductors as a consequence of which they are relatively inaccessible for inspection and maintenance. providing fuse cutouts having an electric fuse convenient for installation and inspection and at the same time capable of being removable and replaceable. In any event, an abnormal electrical condition occurring on a circuit protected by a fuse cutout will destroy. the fuse A1-l though recent experimentation and research have reduced the cost of the replaceable elements, nevertheless such cost is still appreciable and it would be desirable to provide a fuseless cutout which would automatically interrupt the circuit under abnormal electrical conditions and yet wherein it is unnecessary to replace any elements after the protective operation of such cutouts, as is necessary with the fuse cutouts of the prior art.

It is an object of my invention, therefore, to

' provide a new and improved circuit breaker adapted 'to replace the fuse cutouts of the prior art.

It is another object of my invention to provide a new and improved fuseless cutout which is simple and compact, economical in construc- Dimculties have been encountered in I tion, which gives an immediate "and reliable indication of the actuation and lcondition thereof, and which may be used in connection with prior art housings for fuse cutouts.

Further objects and advantages of mv invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexedto and forming a part of this specification.

For a better understanding of my invention, reference may be had to the accompanying drawing in which Fig. 1 is a side view, partly in section of my fuseless cutout in the normal operample, in United States Letters Patent 2,081,813,

granted May 25, 1937, upon an application of B. R. Hermann and assigned to the same assignee as the present application. Housing IIIl is preferably provided with an integrally formed electric: creepage and gas barrier II, disposed between stationary contact assemblies generally indicated at I2 and I3 supported in spaced relationship in housing I0. To the rear oi' the housing I0 is secured a mounting bar I4 for the attachment of the casing to an electric line pole and cross-arm structure or the like. A hinge bracket I5 is suitably secured to the inner rear wall of housing IU in the same manner as are the contact assemblies I2 and I3; preferably these members are cemented in the recesses in the rear Iwall of the housing as shown in the drawing. Bracket l5 includes a pivot pin I6 by means of which a circuit breaker to be described lhereinafter is pivotally supported therefrom.

Contact assemblies I2 and I3 include line terminals I2 and I3' respectively which are adapted tohave line conductors or leads fastened thereto by means of suitable clamping screws or the like. The upper contact assembly I2 comprises a contact finger I1 backed up by means of a spring strip I8 which serves to press the finger I1 downwardly. The -upper contact assembly also includes a terminal clip I8 which is arranged to receive the terminal cap 2li of my improved circuit breaker, which is similar to the terminal caps of the fuse holders of the prior art. The lower contact assembly Il also includes a contacting surface 2i which is adapted to be engaged by a pivotally mounted contact finger 22 similar to the pivoted contact members of prior art construction. In other words the housing III described thus far is adapted to serve as the housing for the fuse cutouts of the prior art as well as the housing for my new and improved fuseless cutout so that prior art constructions employing fuse cutout devices may be readily converted to fuseless cutout invible shunt 42.

stallations, still retaining the same housing in either case.

The open side at the front of housing I6 is closed by means oi' a door or cover 23 preferably constructed of insulating material. This door 23 supports an electric circuit breaker generally indicated at 24 to -be described in greater detail hereinafter. On the outer face of the door or cover 23, there is formed an eyelet handle 26 which may be either .grasped manually orv engaged by a suitable switch stick not shown. The circuit breaker 24 when in the closed position completes the circuit between the contact assemblies I`2 and I3 respectively.

Doorl or cover 23, which as will be described supports circuit breaker 24 is adapted to be pivotally supported by hinge member I6 in suclr a manner that the door and associated circuit breaker may be bodily removed from casing I6 whereupon the contact assemblies I2 and I3 are completely isolated fron one another.

Door mounted circuit breaker 24 preferably comprises a tubular'casing 26 of'insulating material such as ber or the like, which when subjected to the heat of an electric arc evolves an arc-extinguishing gas. Tubular casing 26 is suitably supported in a casting 21 having a casingsupporting opening 2 6 therein. Casting 21 is dicated in Fig. 2, the upward movement thereof being stopped by a tubular liner such as metal suitably bolted to door 23 as by means of bolts or rivets passing through openings 29 best shown 'in Fig. 3. 'I'he casting 21 cooperates with a re-` cess 36 in door 23 to form an enclosure within which certain parts of my electric circuit breaker generally indicated at 24, are locatedas will be described in greater detail hereinafter. The up- Per end of tubular casing 26 is preferably supported by an integralv extension 3| of door 23 which is provided with an opening 32 therein through which tubular casing 26 is adapted to pass. One end of tubular casing 26 is closed by terminal cap 26 as was described above, which is threadedly mounted on the upper end thereof.

A lower terminal 33 for tubular casing 26 is fastened thereto as by any suitable means such as pin 34 and comprises an extension 36 for pivotally supporting contact finger 22 which is biased as by spring means 36 in a, direction to engage the contact surface 2l of the lower contact assembly i3. In order to insure good electrical connection .between pivotally mounted contact finger 22 and the lower contact terminal 33 of tubular casing 26,v I interconnect these members by means of a ilexible shunt 31.

Mounted within tubular casing 26 is a retractable assembly shown in Fig. 2 which comprises an upper terminal button 33, a lower terminal 39, a tension spring 46, a metal tube 4I, and fiex- Upper terminal button 36 is adapted to seat on the upper end of tubular casing 26 so as to be clamped in position by terminal cap 26 with which good electrical contact is made. In order to seal the upper end of tubular casing 26 a suitable gasket 43 as shown in Fig 2 may be provided. The lower terminal 39 of the retractable assembly forms the movable contact of electric circuit breaker 24 and is adapted for reciprocal movement within the bore 44 of tubular casing 26 from an extreme upper position against the lower end of metal tube 4| as shown in Fig. 2 to a position just outside the lower end of casing 26 as shown in Fig. 1. Upper terminal button 36 and movable contact 39 are electrically interconnected by flexible shunt 42. Tension spring 46 tends to draw movable contact 39 into tubular casing 26 to the position intube 4I whose purpose will be described hereinafter. Movable contact 39 which forms the lower terminal of the retractable assembly described above is provided with an annular groove 46 and is adapted to be electrically en gaged by means of an extension 46' on a hinged contact member 46 which although or pivot 41 supported by casting 21 in reces 36 really forms the stationary contact of my circuit breaker 24. In other words, movable contact 39 and cooperating contact 46 form the relatively movable contacts oi' circuit breaker 24 so that relative separation thereof is adapted to draw an arc therebetween' vwithin the bore 44 of tubular casing 26.

The annular groove 46 in movable contact 39 together with a projection 46 of hinged contact 46 which will hereinafter be referred to as stationary contact 46, provides a latching means for holding the relatively movable contacts 39 and 46 in current carrying engagement as shown in Fig. `1 against the action of the retractable assembly including tension spring 46 so long as some means is provided to hold hinged contact member 46 in the position with the extension 46' protruding through opening 21 of casting 21 to engage the annular groove 46 of movable contact 39. In order to hold hinged contact member 46 in the engaged position with movable contact 39, I provide latching means generally indicated at 49, which comprise a tooth 49 on hinged contact 46 which is adapted to engage with a catch 66 supported at the free end of a bimetallic element 6I. This bimetallic element 6I is mounted in the recess 36 as by means of a bimetallic element terminal 62 which is adjustably mounted to a ledge 63 of door 23 in recess 36. The adjustable mounting comprises a slotted opening 64 in bimetallic element terminal 62 which permits adjustment of the catch 66 of the latching means 43 with relation to tooth 49 supported by hinged contact 46. In order that no current may be carried by the latching means 46 including tooth 49 and catch 66. tooth 49 is suitably insulated as indicated at 66 in Fig. 3 from hinged contact 46. A flexible shunt 66 interconnects hinged contact 46 with the free end of bimetallic element 6I to complete the electrical connection therebetween. 'I'he bimetallic element terminal 62 on the other hand is electrically interconnected with the lower terminal 33 of tubular casing 26 by means of exible shunt 61.

Whenever the extension 46' of hinge contact 46 protrudes through opening 21' of casting 21 and is held in the annular groove 46 of movable contact 39 by latching means 46, as shown in Fig. l, the contacts are held in current carrying engagement until release of the latching means as by ilexing of bimetallic element 6I occurs. Manual release of the latching means 46 may be accomplished with the aid of a manually operable plunger or member 66 mounted in the lower part of door, or cover 23, and biased in an outward direction by spring means 69.

lIf plunger 66 is moved inwardly, it engages the slightly movable about hinge with this arrangement withdrawal of contact 3l into tubular casing Il bythe retractable will also cause insulating rod Il to be drawn into tubular casing 2l whereupon an annular bore is defined between the outerl surface of insulating' rod il and the bore Il of tubular casing 2t. This annular bore provides an arc space for the arc drawn upon relative separation of contacts 39 and Il. Insulating rod Il is preferably formed of a gas-evolving insulating material so that the gas evolved therefrom. aids in' the rapid extinguish'ment of the arc drawn upon operation of circuit breaker 2l. By virtue of the annular arc space, more rapid cooling of the arc is provided which consequently speeds up the interrupting process and furthermore the arc is forced or coniined into a relatively small space so as to engage with 'a large area of. insulating material from which gas is evolved when subjected to the heat of an electric arc.

To support door 28 and circuit breaker 2l from pivot pin I8 of bracket IB, a suitable hook-shaped member 62 is provided which is pivotally mounted to casting 21 as indicated at Bl. Hook-shaped member 621s adapted to engage with' the pin I6 of bracket I5 whereupon the door mounted circuit breaker 24 is pivotally mounted so that if terminal clip I9 is disengaged from terminal cap 20, door 23 would pivot about the pin It of bracket I 5 to the open position. I-Iook l2 is provided with -an extension 8l including a guide member BI which engages with insulating rod 6l to guide it in its movement into tubular casing 26 during the circuit interrupting operation. Hook 62 1s also provided with another extension B8 which engages with a tooth l1 on hinged contact 4B so as to prevent pivotal movement of hook 62 relative to bracket 21 about pivot BI when contacts 39 and I6 are in current carrying engagement. In other words the circuit musi:y be broken between relatively movable contacts 39 and before door 23 can drop open.

As soon as extension IB is released from engagement with tooth 61 the circuit breaker assembly is permitted to move downwardly both by virtue of gravity and the force of spring backed contact linger I1 about pivot Il so that terminal clip I9 is released from terminal cap 20 by the downward movement of the entire door-mounted circuit breaker 2l, whereupon the door drops to the open position. If it is desired to prevent the door from moving to the open position on the occurrence of a circuit-interrupting operation, a suitable screw may be insertedin opening 6B of hook 62 to engage with casting 21 thereby preventing pivotal movement about pivot 63.

In the collapsed position of the retractable assembly as was mentioned above, movable contact 39 engages with the end of metal tube 4|. The purpose of this is to prevent the high gas pressures formed within the bore M, of tubular casing 26 upon a circuit interrupting operation, from acting on the upper surface of movable contact 39 to force the contact back to the closed circuit position.

In order to aid in resetting the circuit breaker 2l hinged contact 4B is provided with a manual lever 69 which extends out of the enclosure formed between casting 21 and the door 23.

With the door mounted circuit breaker 2| in the position indicated in Fig. 2, reclosing of the circuit through the fuseless cutout is accomably be formed at the lower end thereof so as v to provide a suitable grip for resetting. is grasped and pulled downwardly at the same time that -manual lever Il of hinged contact 48 is moved upwardly so that extension 'II' thereof may protrude through opening 21' of casting 21 to make contact with movable contact 39 by engaging the annular groove 4l formed therein. 'I'he upward movement of manual lever 09 of hinged contact 4B will cause tooth 49 to engage with catch III of bimetallic thermal element 5I. Flexing of bimetallic thermal element 5l, either due to an abnormal current flowing therethrough or manually by operating plunger 68 will cause'release of latching means 4B and consequent interruption of the circuit within the annular bore formed between insulating rod III and the interior surface of tubular casing 2B. The interrupting operation is always performed between relatively movable contacts l! and so that when the door 2l moves to the open position, taking with it door mounted circuit breaker 2l, an isolating action between the contact assemblies including terminal assemblies I2 and I3 is provided. The position of insulating rod III with or without the opening of door 2l gives a clear visual indication of whether the .fuseless cutout of my invention has operated and requires resetting. Also the- `after circuit interruptionl it being merely necessary for the lineman to reclose the circuit breaker in the manner described above. Also, an indication of the condition of the fuseless `cutout is at all times evident to the lineman.

Furthermore, a suitable arc interrupting means for eiliciently interrupting the relatively high voltages found on distribution circuits is incorporated in the device.

While I have shown and described a particular embodiment of my invention for a fuseless cutout, I do not desire my invention to be limited to the construction shown and described, for it will, of course, be obvious that changes and modications may be made without departing from my invention and I therefore aim in the 'appended claims to cover all such changes and modifica.-

` tions as fall within the true spirit and scope of plished by ilrst removing the d oor 23 and circuit breaker 2l mounted thereon from housing lll. Next the insulating rod ll which should prefermy invention.

What I claim as new and desire to secure by letters Patent of the United States is:

1.-"= In an electric switching device, the combination of ahousing and a cover for closing an open side of said housing, a circuit interrupter mounted .on said cover comprising a pair of relatively movable contacts, a recess in said cover, and bimetallic means mounted in said recess for initiating relative separation of said contacts to'interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said'contacts may be reclosed to reestablish an electric circuit therethrough.

2. In an electric switching device, the combination of a. housing and a cover for closing an open side of said housing. a circuit lnterrupter mounted on said cover comprising a pair of relameans for causing relative separation oi said contacts, and latching means including bisaid contacts to interrupt the circuit associatedwith said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough. y

3. In an electric switching device, the combination of a housing and a cover for closing an open side of said housing, a circuit interrupter mounted on said cover comprising a tubular casing, a pair oi' relatively movable contacts, one of which is mounted in said casing, a recess in said cover, and bimetallic means mounted in said recess for initiating relative separation oi' said contacts to interrupt lthe circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

4. In an electric switching device, the combination of a housing and a door for closing an open side of said housing, a circuit interrupter mounted on said door comprising a tubular casing, a pair of relatively movable contacts, one of which is mounted in said casing, means for deiining an annular arc space in said casing so that the arcv drawn upon relative separation of said contacts is conned in said annular arc space yfor rapid extinguishment thereoi, a recess in said door, and bimetallic means mounted in said recess for initiating relative separation of said contacts to interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

5. In an electric switching device, the combination oi' a housing and a door for closing an open side of said housing, a circuit interrupter mounted on said door comprising a tubular casing, a pair oi.' relatively movable contacts comprising a movable contact mounted in said casing and a cooperating contact member located outside said casing and adapted to be in current carrying engagement with said movable contact when said movable contact is moved out of said casing, a retractable contact assembly in said casing for causing withdrawal of said movable contact into said'casing and relative separation f of said contacts, a rod of arc extinguishing material connected. to said movable contact so as to be drawn into said casing to deilne an annular arc space therein upon relative separation ot said contacts, latching means for holding said contacts in current carrying engagement against the force of said retractable assembly, a recess in said door. and bimetallic means mounted in said recess for initiating relative separation of said contacts to interrut the circuit associated with said device by causing release oi' said latching means, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

6. In an electric switching device, the combination of a housing and a cover for closing an open side of said housing, a circuit interrupter mounted on said cover comprising a pair of relatively movable contacts, a recess in said cover and means mounted in said recess for initiating relative separation of said contacts to interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

'1. In an electric switching device, the combination of a housing and a cover for closing an open side of said housing, a circuit interrupter mounted on said cover comprising a pair of relatively movable. contacts, a recess in said cover, means for causing relative separation of said contacts, and latching means including additional means mounted in said recess for rendering said iirst mentioned means ineffective, said additional means being arranged upon predetermined current conditions to permit said first mentioned means to cause relative separation of said contacts to interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

8. In an electric switching device, the combination of a housing and a cover tor closing an open side of said housing, a circuit interrupter mounted on said cover comprising a tubular casing, a pair of relatively movable contacts, one of which is mounted in said casing, a.recess in said cover, and means mounted in said recess for initiating relative separation oi.' said contacts to interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

9. In an electric switching device, the combination of a housing and a door for closing anopen side of said housing, a circuit interrupter mounted on said door comprising a tubular casing, a pair of relatively movable contacts, one of which is mounted in said casing, means i'or dening an annular arc space in said casing so that the arc drawn upon relative separation ci said contacts is conned in said annular arc space for rapid extinguishment thereof, a recess in said door, and means mounted in said recess for initiating relative separation of said contacts to interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

10. In an electric switching device, the combination of a housing and a cover for closing an open side of said housing, a circuit interrupter mounted on said cover comprising a tubular casing, a pair of relatively movable contacts comprising a movable contact mounted in said casing and a cooperating contact member located outside said casing and adapted to be in current carrying engagement with said movable contact when said movable contact is moved out oi' said casing, a retractable contact assembly in said casing for causing withdrawal of said movable contact into said casing and relative separation oi said contacts, a rod of arc-extinguishing material connected to said movable contact so as to be drawn into said casing to define an annular arc space therein upon relative separation of said contacts, latching means for holding said contacts in current carrying engagement against the force of said retactable assembly, a recess in said cover, and means mounted in said recess forv initiating relative separation oi said contacts to interrupt the circuit associated with said device by causing release oi said latching means. said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

il. In an electric switchingA device, the combination of a housing and a recessed cover for closing an open side of said housing, a circuit interrupter mounted on said recessed cover comprising a pair of relatively movable contacts, means for causing relative separation of said contacts, and latching means including bimetallic means mounted in said recessed cover tor rendering said iirst mentioned means ineiective, said bimetallic means being arranged upon predetermined current conditions to permit said nrst mentioned means to cause relative separation of said contacts to interrupt the circuit associated with said device, said circuit interrupter being s'o constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

12. In an electric vswitching means, the combination of a housing and`a recessed cover for closing an open side oi said housing, a circuit interrupter mounted on said recessed cover comprising a pair of relatively movable contacts, and

means mounted in said recessed cover for initiating relative separation of said contacts to interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

13. In an electric switching device, the combination of an insulating support, a circuit interrupter hingedly mounted on said support comprising a tubular casing, a pair of relatively movable contacts one f which is mounted in said casing, means i'or defining aniannular arc space in said casing so that the arc drawn upon relative separation of said contacts is coniined in said annular arc space for rapid extinguishment thereof, an enclosure associated with said support, and means mounted in said enclosure for initiating relative separation of said contacts to interrupt the circuit associated with said device, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

14.v In an electric switching device, the combination of an insulating support, a circuit interrupter hingedly mounted on said support comprising a tubular casing, a pair of relatively movable contacts comprising a movable contact mounted in said casing and a cooperating contact member located outside said casing and adapted to be in current carrying engagement with said movable contact when said movable contact is moved out of said casing, a retractable contact assembly in said casing .for causing withdrawal of said movable contact into said casing and relative separation oi' said contacts, a rod of arc extinguishing material connected to said movable contact so as to be drawn into said casing to deiine an annular arc space therein upon relative separation of said contacts, latching means for.

holding said contacts in current carrying engagement against the force of said retractable assembly, an enclosure associated with said support, and means mounted in said enclosure for initiating relative separation of said contacts to interrupt the circuit associated with said device by causing release of said latching means, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish and electric circuit therethrough.

15. In an electric switching device, the combination of a housing and a door for closing an mounted on said door comprising a tubular casing, a pair oi' relatively movable contacts comprising a movable contact mounted in said casing and a cooperating contact member' located outside said casing and adapted to be in current carrying engagement with said movable contact -when said movable contact is moved out of said casing, a retractable contact assembly in said casing for causing withdrawal of said movable contact in to said casing and relative separation of said contacts, a rod of arc extinguishing material connected to said movable contact so as to be drawn into said casing to detlne an annular arc space therein upon relative separation of said contacts, latching means for holding said ccntacts in current carrying engagement against the force of said retractable assembly, and bimetallic means mounted in -said housing for initiating relative separation of said contacts to interrupt the circuit associated with said device by causing release oi' said latching means, said circuit interrupter being so constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.l i

16. In an electric switching device, the combination of a housing and a door for closing an open side of said housing, a circuit interrupter mounted on said door comprising a tubular casing, a pair of relatively movable contacts one oi! which is mounted in said casing, kmeans for deiining an annular are space in said casing so that *thek arc drawn upon relative separation of said contacts is conned insaid annular arc-space for rapid extinguishmentthereof, and bimetallic means mounted in said housing rfor initiating relative separation o! said contacts to interrupt the circuit associated with saiddevice, said circuit interrupter being so constructed and arranged that said contacts may .be reclosed to reestablish an electric circuit therethrough.

17. In an electric switching device, the combination of an insulating support, a circuit interrupter hingedly mounted on said support comprising a tubular casing, a pair of relatively movable contacts associated with said casing, one of which is adapted for reciprocal movement in said casing, a tubular liner for a portion of said casing, means i'or causing relative separation of said contacts to draw an arc in said casing and to cause o ne of said contacts to move into said casing to engage an end of said tubular liner whereby high gas pressures produced in said tubular casing upon the drawing of an arc in said casing cannot force said one contact toward the closed circuit position.

18. In an electric switching device the combination of a housing and a recessed cover for closing an open side of said housing, a circuit interrupter mounted on said recessed cover comprising a pair or relatively movable contacts, means mounted in said recessed cover for initiating relative separation of said contacts to interrupt the circuit associated with said device, and means engageable exterlorly of said housing but extending into said recessed cover for causing release o! said means mounted in said recessed cover when manually operated, said circuit interrupter being sc constructed and arranged that said contacts may be reclosed to reestablish an electric circuit therethrough.

19. In an electric switching device the combination of a housing and a recessed cover for closing an open *side of said housing. a circuit drop-out motion.

interrupter mounted on said recessed cover comprising a pair oi' relatively movable contacts, bimetallic vmeans mounted in said recessed cover for initiating relativeseparation of said contacts to interrupt the circuit associated with said device, and a spring biased member engageable exteriorly of said housing but extending into said recessed cover for release ot said bimetallic means when manually operated, said circuit interruptor being so constructed and arranged that said conl0 tacts may be. reclosed to reestablish an electric circuit therethrough 20. A cut-out construction comprising a tube having an open end, a conductor within said tube and having a portion projecting outwardly from the open end o! said tube. a pair o! stationary contacts normally electrically connected by said conductor, retracting means within said tube tending to draw said conductor into said tube, restraining means adjacent the open end or said tube for detachably holding the outwardly projecting portion of said conductor,l and manually operable means for causingrelease oi said conductor from said restraining means, whereby electrical connection between said stationary contacts will be interrupted within said tube.

21. A drop-out cut-out construction comprising a tube having an open end, a conductor within said tube having a portion projecting outwardly from the open end of said tube, a pair o! stationary contacts normally electrically connected by said conductor, retracting means within said tube tending to draw said conductor into said tube, means supporting said tube for drop-out motion, said tube being biased towards drop-out motion, restrainnig means detachably restrain#- ing said conductor and restraining ysaid tube against drop-out motion and when released from said conductor allowing said tube to execute dropout motion. and manually operable means for causing release o! said conductor from said restraining means, whereby electrical connection between said stationary will be interrupted within said tube and said tube will execute 22. A cut-out construction comprising a tube having an open end and a closed end, a conductor within said tube having a normally projecting portion projecting outwardly from the open end of said tube, said tube having s terminal adjacent 5 its closed end and having a terminal provided with a portion adjacent its open end, a pair of 5 said tube, restraining means adjacent the open end of said tube for detachably holding the normally outwardly projecting portion or said conductor, and operable means for causing release of said conductor from said restraining means, the said portion of the terminal o! the tube adjacent the open end being arranged in close prox imity to said normally outwardly projecting portion whereby when said normally outwardly projecting portion is retracted the arc will be establl lished between the last mentioned terminal o! the tube and the normally projecting portion of said conductor and the circuit will be interrupted within said tube.

23. A cut-out construction comprising a tube I0 having an open end. a conductor within said tube and having a portion projecting outwardly from the open end ot said tube, a pair o! stationary contacts normally electrically connected by said conductor, retracting means within said tube :s tending to draw said conductor into said. tube,

restraining means adjacent the vopen end of said .tube for detachably holding the outwardly projecting portion of said conductor, and means for causing release of said conductor from said ro- 80 straining means, whereby electrical connection between said stationary contacts will be interrupted within said tube.

24. A drop-out cut-out construction comprising a tube having an open end, a conductor withst'fm said tube having a portion projecting outwardly from the open end oi' said tube, a pair of stationary contacts normally electrically connected by said conductor, retracting means within said tube tending to draw said conductor into 40 said tube. means supporting said tube i'or dropout motion, said tube being biased towards dropout motion, restraining means detachably restraining said conductor and restraining said tube against drop-out motion and when released from l said conductor snowing said tube to execute drop-out motion. and means i'or causing'release of said conductor from said restraining means, whereby electrical connection between said stationary contacts will be interrupted within said tube and said tube will execute drop-out motion.

SIDNEY R. SMITH, Ja. 

